This invention relates generally to ultrasound probes, and more particularly, to probes for ultrasound medical imaging systems.
Ultrasound systems typically include ultrasound scanning devices, such as, ultrasound probes having different transducers that allow for performing various different ultrasound scans (e.g., different imaging of a volume or body). The ultrasound probes are typically connected to an ultrasound system for controlling the operation of the probes. The probes include a scan head having a plurality of transducer elements (e.g., piezoelectric crystals), which may be arranged in an array. The ultrasound system drives the transducer elements within the array during operation, such as, during a scan of a volume or body, which may be controlled based upon the type of scan to be performed.
Proper acoustical contact is needed to produce images of acceptable resolution when using phased array probes in ultrasound imaging. Proper acoustical contact is needed because in phased array probes a large part of the aperture of the probe is used for steering and focusing along each beam direction during image formation. A reduction of acoustical contact for portions of the probe surface will result in poor image resolution that may be observed as a smearing in the lateral direction of the image.
When using an ultrasound probe to scan a patient, improper acoustical contact may arise from different factors. For example, poor skin contact may be caused by use of an insufficient amount of contact gel, especially when the probe surface is not parallel to the skin surface. In cardiac imaging, proper probe contact with the patient skin can be hard to achieve due to the narrow acoustic window between the patient's ribs. An individual performing an ultrasound scan often must view a display screen, move the probe and adjust the probe settings to ensure good probe placement and acoustic contact for a given imaging application.
In operation, the experienced examiner may recognize the occurrence of, for example, poor lateral image resolution, and then adjust the probe position to improve image occurrence of poor lateral image resolution (e.g., adjust the probe position to improve image quality). However, this is a time consuming and often difficult process. For less experienced users, identifying these problems and performing operations to correct for the problems is even more difficult, thereby resulting in less than acceptable images (e.g., inability to perform proper diagnosis based on the image).
Additional factors may cause problems with providing proper probe placement. For example, phase aberrations due to, for example, fat/muscle layers in the body wall will typically create amplitude variations in the ultrasound wave fronts. This may further cause problems with proper placement of an ultrasound probe to obtain acceptable images because of an inability to identify the degree of amplitude variation.